LFTR vs Nuclear Waste
It is transuranics like plutonium, americium & curium which present the biggest challenge to nuclear waste disposal. They have moderate half-lives (neither decay quickly nor low levels of radiation) and have complicated decay chains.
All of today’s pressurized water reactors (every commercial reactor operating in North America) use less than 1% of the energy stored in the nuclear fuel. This is why the spent fuel rods are difficult to manage. LFTR can consume almost all of its fuel. This big increase in efficiency means less nuclear waste to deal with.
And because LFTR (Liquid Fluoride Thorium Reactor) uses LIQUID fuel, it is far easier to partition the “waste” to extract valuable by-products, such as medical isotopes for cancer treatment.